Packaging adhesive film and thin-film photovoltaic module

Abstract

The utility model relates to a packaging adhesive film and a thin-film photovoltaic module. The packaging adhesive film comprises a first adhesive layer, an adhesive layer and a second adhesive layer which are stacked in sequence, the adhesive layer is positioned between the first adhesive layer and the second adhesive layer; the water vapor transmission rate of the first adhesive layer is less than 5g / m < 2 > / 24h; the tensile strength of the second adhesive layer is greater than 20Mpa; the packaging adhesive film is a melt co-extrusion adhesive film. The packaging adhesive film provided by the utility model can improve the water blocking performance, the mechanical performance and the bonding performance of the packaging adhesive film, further improves the safety performance of the packaging adhesive film, reduces the cost, and is beneficial to solving the safety related problems of a thin film photovoltaic module in a building integrated photovoltaics (BIPV) project.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic component packaging, in particular to a packaging film and a thin-film photovoltaic component. Background Art

[0002] The design and application of BIPV (Building Integrated Photovoltaic) must meet multiple requirements, including safety, compliance with national building codes, aesthetics, and maintenance requirements. Currently, the encapsulation films used in thin-film photovoltaic modules are typically made of ethylene vinyl acetate (EVA), polyolefin elastomer (POE), or "EVA-POE-EVA" (EPE) composite structural films. These films have low mechanical and adhesive properties, pose a lower safety risk if the backplane glass is damaged, and are relatively expensive.

[0003] Therefore, there is a need for an encapsulation film suitable for BIPV thin-film photovoltaic modules to improve the mechanical properties and bonding properties of the encapsulation film, thereby solving safety-related issues of thin-film photovoltaic modules in BIPV projects. Utility Model Content

[0004] Therefore, the present invention provides an encapsulation film and a thin-film photovoltaic module to solve the problems of low mechanical and adhesive properties of the existing encapsulation films used in thin-film photovoltaic modules, low safety after the back glass is damaged, and high cost.

[0005] The utility model provides an encapsulation film for encapsulating thin-film solar cell chips and backplane glass, the encapsulation film comprising:

[0006] A first adhesive layer, a bonding adhesive layer, and a second adhesive layer stacked in sequence; the bonding adhesive layer is located between the first adhesive layer and the second adhesive layer;

[0007] The water vapor transmission rate of the first adhesive layer is less than 5g / m 2 / 24h; the tensile strength of the second adhesive layer is greater than 20Mpa;

[0008] The packaging film is a melt co-extruded film.

[0009] Optionally, the first adhesive layer is a non-polar material;

[0010] The second adhesive layer is a polar material;

[0011] The adhesive layer is a grafting polymer.

[0012] Optionally, the first adhesive layer is a POE adhesive layer or a TPO (Thermoplastic Polyolefin) adhesive layer;

[0013] The second adhesive layer is a TPU (Thermoplastic Polyurethane) adhesive layer or a PVB (Polyvinyl Butyral) adhesive layer.

[0014] Optionally, when the first adhesive layer is a POE adhesive layer, the bonding adhesive layer is a POE-G-MAH (maleic anhydride grafted polyolefin) layer;

[0015] When the first adhesive layer is a TPO adhesive layer, the bonding adhesive layer is a PP-G-MAH layer (maleic anhydride grafted polypropylene).

[0016] Optionally, the first adhesive layer is a POE adhesive layer, the second adhesive layer is a TPU adhesive layer, and the bonding adhesive layer is a POE-G-MAH layer.

[0017] or:

[0018] The first adhesive layer is a TPO adhesive layer, the second adhesive layer is a PVB adhesive layer; and the bonding adhesive layer is a PP-G-MAH layer.

[0019] Optionally, the thickness of the first adhesive layer is 250 μm to 350 μm;

[0020] The thickness of the second adhesive layer is 350 μm to 450 μm;

[0021] The thickness of the adhesive layer is 50 μm to 100 μm.

[0022] Optionally, the first adhesive layer is an insulating adhesive layer;

[0023] The first adhesive layer, the second adhesive layer and the bonding adhesive layer are all transparent film layers.

[0024] The utility model also provides a thin-film photovoltaic module, comprising the above-mentioned encapsulation film; and further comprising:

[0025] a thin-film solar cell chip, located on a surface of the first adhesive layer facing away from the bonding adhesive layer;

[0026] The back panel glass is located on the surface of the second adhesive layer facing away from the bonding adhesive layer.

[0027] Optionally, the first adhesive layer is suitable for connecting the thin-film solar cell chip;

[0028] The second adhesive layer is suitable for connecting to the back panel glass.

[0029] Optionally, the thin-film solar cell chip includes a transparent or semi-transparent substrate and a thin-film solar cell prepared on the substrate;

[0030] The thin film solar cell includes a perovskite solar cell.

[0031] The technical solution of the utility model has the following advantages:

[0032] (1) The encapsulation film provided by the present invention includes a first adhesive layer, an adhesive layer, and a second adhesive layer stacked in sequence by melt co-extrusion. The adhesive layer is used to bond the first adhesive layer with a lower water vapor permeability to the second adhesive layer with a higher tensile strength, thereby improving the water barrier performance, mechanical properties and bonding performance of the encapsulation film, thereby improving the safety performance of the encapsulation film, reducing costs, and helping to solve safety-related issues of thin-film photovoltaic modules in BIPV projects.

[0033] (2) The encapsulation film and thin-film photovoltaic module provided by the present invention have a first adhesive layer suitable for connecting thin-film solar cell chips, which can improve the sealing performance of thin-film solar cell chips; the adhesive layer is used to connect the first adhesive layer and the second adhesive layer, which can improve the affinity of the interface between the two adhesive layers and enable the two adhesive layers to be effectively bonded; the second adhesive layer is suitable for connecting the back panel glass, which can improve the safety of the back panel glass. Even if the glass is broken, the fragments will be stuck to the second adhesive layer. The second adhesive layer has strong support, which effectively prevents the occurrence of fragments piercing and penetrating and falling incidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 This is a schematic structural diagram of a packaging film according to an embodiment of the present invention;

[0036] Figure 2 The figure is a schematic structural diagram of a thin-film photovoltaic module according to an embodiment of the present invention.

[0037] Description of reference numerals:

[0038] 1-first adhesive layer; 2-adhesive layer; 3-second adhesive layer; 100-coextruded encapsulation film; 200-thin-film solar cell chip; 300-backplane glass. DETAILED DESCRIPTION

[0039] In order to solve the problems of low mechanical and adhesive properties of existing thin-film photovoltaic module encapsulation films, low safety after the back glass is damaged, and high cost, the utility model provides an encapsulation film for encapsulating thin-film solar cell chips and back glass, the encapsulation film comprising: a first adhesive layer, an adhesive layer, and a second adhesive layer stacked in sequence; the adhesive layer is located between the first adhesive layer and the second adhesive layer; the water vapor transmission rate of the first adhesive layer is less than 5g / m 2 / 24h; the tensile strength of the second adhesive layer is greater than 20Mpa; the encapsulating film is a melt co-extruded film.

[0040] The utility model also provides a thin-film photovoltaic module, comprising the above-mentioned encapsulating film; and further comprising: a thin-film solar cell chip located on the surface of the first adhesive layer facing away from the bonding adhesive layer; and a backplane glass located on the surface of the second adhesive layer facing away from the bonding adhesive layer.

[0041] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. In the description of the present invention, it should be noted that the terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0042] Example 1

[0043] refer to Figures 1 and 2 This embodiment provides a packaging film 100, including:

[0044] A first adhesive layer 1, a bonding adhesive layer 2, and a second adhesive layer 3 are stacked in sequence; the bonding adhesive layer 2 is located between the first adhesive layer 1 and the second adhesive layer 3;

[0045] The water vapor permeability of the first adhesive layer 1 is less than 5g / m 2 / 24h; the tensile strength of the second adhesive layer 3 is greater than 20Mpa;

[0046] The packaging film 100 is a melt co-extruded film.

[0047] In a specific implementation, the first adhesive layer 1, the bonding adhesive layer 2, and the second adhesive layer 3 are suitable for being formed by melt co-extrusion.

[0048] The encapsulation film provided in this embodiment includes a first adhesive layer, an adhesive layer, and a second adhesive layer stacked in sequence formed by melt co-extrusion. The adhesive layer is used to bond the first adhesive layer with a low water vapor permeability to the second adhesive layer with a high tensile strength. This can improve the water barrier properties, mechanical properties and bonding properties of the encapsulation film, thereby improving the safety performance of the encapsulation film, reducing costs, and helping to solve safety-related issues of thin-film batteries in BIPV projects.

[0049] Furthermore, in this embodiment, the first adhesive layer 1 is made of a non-polar material;

[0050] The second adhesive layer 2 is a polar material;

[0051] The adhesive layer 3 is a grafting polymer.

[0052] During specific implementation, since the first adhesive layer 1 is a non-polar material and does not contain polar groups in its molecular structure, placing the first adhesive layer 1 close to one side of the thin-film solar cell chip can improve the sealing of the thin-film solar cell chip and achieve an excellent anti-PID effect; the second adhesive layer 3 is a polar material with high tensile strength and is close to the side of the back panel glass. When the component is impacted by external force, even if the glass breaks, the fragments will be stuck to the second adhesive layer 3, and the second adhesive layer 3 will not be penetrated, which can fully meet the safety performance requirements of the building. In addition, since the adhesion between the interfaces of polymer blends of different polarities is very weak, they will separate from each other after wet and hot aging. However, by providing an adhesive layer 2 so that the adhesive layer 2 is located between the first adhesive layer 1 and the second adhesive layer 3, the affinity of the interface between the two adhesive layers can be improved, so that the two adhesive layers can be effectively bonded.

[0053] In specific implementation, since the grafting polymer has active groups and a chemical structure similar to that of the adhesive layer, the adhesive layer is selected from the grafting polymer, which can reduce the size of the dispersed phase and increase the interfacial bonding force, thereby improving the compatible interface between the polar adhesive film and the non-polar adhesive film.

[0054] The encapsulation film provided by the present invention has a first adhesive layer suitable for connecting thin-film solar cell chips, which can improve the sealing of thin-film solar cell chips; the bonding adhesive layer is used to connect the first adhesive layer and the second adhesive layer, which can improve the affinity of the interface between the two adhesive layers and enable the two adhesive layers to be effectively bonded; the second adhesive layer is suitable for connecting the back panel glass, which can improve the safety of the back panel glass. Even if the glass is shattered, the fragments will be stuck to the second adhesive layer. The second adhesive layer has strong support, which effectively prevents the occurrence of fragments puncturing and penetrating and falling incidents.

[0055] Furthermore, in this embodiment, the first adhesive layer 1 is a POE adhesive layer or a TPO adhesive layer;

[0056] The second adhesive layer 3 is a TPU adhesive layer or a PVB adhesive layer.

[0057] Conventional thin film modules are usually encapsulated with EVA or EPE films, but the safety of these films cannot be guaranteed after the back glass is damaged. The water vapor transmission rate of EVA film is relatively high (generally 20g / m 2 / 24h~40g / m 2 / 24h), acetic acid is produced when it comes into contact with water, which will damage the thin-film solar cell chip. Acetic acid reacts with the alkali on the glass surface to produce sodium ions. Under the action of an external electric field, the sodium ions move to the surface of the thin-film solar cell chip and accumulate in the anti-reflection layer, thereby causing PID phenomenon.

[0058] In this embodiment, the first adhesive layer 1 is a POE adhesive layer or a TPO adhesive layer. Since the water vapor permeability of the POE adhesive layer and the TPO adhesive layer is only about 1 / 8 of that of the EVA film, and they are non-polar materials, they will not decompose and produce acetic acid when exposed to water. At the same time, the volume resistivity of the POE adhesive layer and the TPO adhesive layer (at 1.0×10 14 ~1.0×10 15 The second adhesive layer 3 is a TPU adhesive layer or a PVB adhesive layer. Since the tensile strength of the PVB adhesive layer is 25Mpa-45Mpa, and the tensile strength of the TPU adhesive layer is 50Mpa-70Mpa, and the TPU adhesive layer and the PVB adhesive layer have common characteristics such as high bonding strength, penetration resistance, aging resistance, sound insulation, and safety, when connecting the back panel glass, the glass fragments will be adhered to the second adhesive layer, which can effectively prevent the glass from shattering and injuring people. Falling objects cannot penetrate the second film layer, thus providing safety protection for the module.

[0059] Furthermore, in this embodiment, when the first adhesive layer 1 is a POE adhesive layer, the bonding adhesive layer 2 is a POE-G-MAH layer;

[0060] When the first adhesive layer 1 is a TPO adhesive layer, the bonding adhesive layer 2 is a PP-G-MAH layer.

[0061] Furthermore, in this embodiment, the first adhesive layer 1 is a POE adhesive layer, the second adhesive layer 3 is a TPU adhesive layer; and the bonding adhesive layer 2 is a POE-G-MAH layer.

[0062] TPU film has the following characteristics: (1) Higher strength: With the same glass structure and thickness, it has higher load and wind pressure resistance; (2) Better safety after breakage: TPU film has higher tensile strength and tear strength, and laminated glass still has strong support after breakage; (3) Better optical performance: TPU film has higher light transmittance and lower haze, and has higher transparency and visual effect when compounded with glass. Therefore, TPU interlayer has higher bonding, optical and mechanical properties, making it suitable as an encapsulation film for BIPV thin-film photovoltaic modules. In addition, the cost of TPU film is lower than that of POE film.

[0063] POE film is a thermoplastic elastomer that combines the advantages of both plastic and rubber. Its key features include excellent mechanical properties such as high elasticity, high strength, and high elongation, as well as good low-temperature performance. Furthermore, it exhibits excellent water resistance and resistance to PID (potential-induced degradation), making it a key material in photovoltaic packaging. However, POE film is relatively expensive, has a lower transmittance than TPU film, and lacks safety assurance.

[0064] Blending POE and TPU films presents the following challenges. First, there's the molecular weight difference. Polyolefins have molecular weights in the millions, significantly higher than those of polyurethane and other blending components, resulting in a significant difference in melt viscosity. Second, there's the difference in molecular polarity. Polyolefins are non-polar polymers, while polyurethanes are polar. The interfacial adhesion between polymer blends of different polarities is weak, leading to separation. Therefore, a POE-G-MAH layer is required as the adhesive layer.

[0065] In one example, a non-cross-linked TPU film and a POE film are hot-melt extruded to form a film, which not only retains the advantages of the TPU film such as high strength, high safety performance, and low cost, but also achieves the characteristics of the POE film such as high volume resistivity and low water vapor permeability. At the same time, in order to solve the compatibility problem between the two, POE-G-MAH is added as a compatibilizer during co-extrusion of the film. Since POE-G-MAH has active groups and similar chemical structures, it can reduce the size of the dispersed phase and improve the interfacial bonding force. In addition, since the cost of TPU film is lower than that of POE film, this solution can not only reduce the amount of POE used to achieve the purpose of cost reduction. Therefore, the encapsulation film provided in this example has a simple structure, low cost, excellent bonding between the first adhesive layer 1 and the second adhesive layer 3, and high impact resistance.

[0066] The encapsulation film provided by the utility model comprises a first adhesive layer of a POE adhesive layer, which has excellent mechanical properties such as high elasticity, high strength, and high elongation, good low-temperature performance, and excellent water barrier and PID resistance; a second adhesive layer of a TPU adhesive layer, which has high tensile strength and tear strength, high light transmittance and low haze, as well as high bonding performance; and a bonding adhesive layer of a POE-G-MAH layer, which can increase the polarity of the polyolefin elastomer through a grafting reaction, thereby making it more compatible with polar polymer materials such as polyurethane.

[0067] Furthermore, in this embodiment, the first adhesive layer 1 is a TPO adhesive layer, the second adhesive layer 3 is a PVB adhesive layer, and the bonding adhesive layer 2 is a PP-G-MAH layer.

[0068] The encapsulation film provided by the utility model has a first adhesive layer of TPO adhesive layer, which has low water vapor permeability, high volume resistivity, long service life, excellent water barrier performance and anti-PID performance; the second adhesive layer is PVB adhesive layer, which has high bonding strength, penetration resistance and aging resistance; the bonding adhesive layer is a PP-G-MAH layer, which can increase the polarity of TPO through grafting reaction, making it more compatible with polar polymer materials such as PVB.

[0069] Furthermore, in this embodiment, the thickness of the first adhesive layer 1 is 250 μm to 350 μm, for example, 250 μm, 280 μm, 300 μm, or 350 μm;

[0070] The thickness of the second adhesive layer 3 is 350 μm to 450 μm, for example, 350 μm, 380 μm, 400 μm, or 450 μm;

[0071] The thickness of the adhesive layer 2 is 50 μm to 100 μm, for example, 50 μm, 70 μm, 80 μm, or 100 μm.

[0072] Furthermore, in this embodiment, the first adhesive layer 1 is an insulating adhesive layer;

[0073] The first adhesive layer 1 , the second adhesive layer 2 and the bonding adhesive layer 3 are all transparent film layers.

[0074] Specifically, the first adhesive layer 1 is an insulating adhesive layer, and the volume resistivity of the first adhesive layer 1 is greater than 1.0 / 10 15 Ω·cm, which helps to improve the electrical insulation performance of the component and achieve excellent anti-PID (potential induced degradation) effect; the first adhesive layer 1, the second adhesive layer 2 and the bonding adhesive layer 3 are all transparent film layers, which can improve the light transmittance of the component, so that the encapsulation film and the back panel glass have higher transparency and visual effect after being compounded.

[0075] Example 2

[0076] The present invention further provides a thin-film photovoltaic module, characterized in that it includes the encapsulation film 100 of the above-mentioned embodiment 1, and further includes:

[0077] The thin-film solar cell chip 200 is located on the surface of the first adhesive layer 1 facing away from the adhesive layer 2;

[0078] The back glass 300 is located on the surface of the second adhesive layer 3 facing away from the bonding adhesive layer 2 .

[0079] Furthermore, in this embodiment, the first adhesive layer 1 is suitable for connecting the thin-film solar cell chip 200;

[0080] The second adhesive layer 3 is suitable for connecting to the back glass 300 .

[0081] The thin-film photovoltaic module provided by the present invention has a first adhesive layer suitable for connecting thin-film solar cell chips, which can improve the sealing of the thin-film solar cell chips; the adhesive layer is used to connect the first adhesive layer and the second adhesive layer, which can improve the affinity of the interface between the two adhesive layers and enable the two adhesive layers to be effectively bonded; the second adhesive layer is suitable for connecting the back panel glass, which can improve the safety of the back panel glass. Even if the glass is shattered, the fragments will be stuck to the second adhesive layer. The second adhesive layer has strong support, which effectively prevents the occurrence of fragments of puncture and penetration and falling incidents.

[0082] Furthermore, in this embodiment, the thin-film solar cell chip 200 includes a transparent or semi-transparent substrate and a thin-film solar cell fabricated on the substrate;

[0083] The thin film solar cell includes a perovskite solar cell.

[0084] Furthermore, in some embodiments, the substrate is located on a side of the thin-film solar cell facing away from the first adhesive layer 1 .

[0085] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A packaging film, characterized in that: include: A first adhesive layer, a bonding adhesive layer, and a second adhesive layer stacked in sequence; the bonding adhesive layer is located between the first adhesive layer and the second adhesive layer; The water vapor transmission rate of the first adhesive layer is less than 5g / m 2 / 24h; the tensile strength of the second adhesive layer is greater than 20Mpa; The packaging film is a melt co-extruded film.

2. The packaging film according to claim 1, wherein The first adhesive layer is a non-polar material; The second adhesive layer is a polar material; The adhesive layer is a grafting polymer.

3. The packaging film according to claim 2, wherein: The first adhesive layer is a POE adhesive layer or a TPO adhesive layer; The second adhesive layer is a TPU adhesive layer or a PVB adhesive layer.

4. The packaging film according to claim 3, characterized in that When the first adhesive layer is a POE adhesive layer, the bonding adhesive layer is a POE-G-MAH layer; When the first adhesive layer is a TPO adhesive layer, the bonding adhesive layer is a PP-G-MAH layer.

5. The packaging film according to claim 4, characterized in that The first adhesive layer is a POE adhesive layer, the second adhesive layer is a TPU adhesive layer; the bonding adhesive layer is a POE-G-MAH layer; or: The first adhesive layer is a TPO adhesive layer, the second adhesive layer is a PVB adhesive layer; and the bonding adhesive layer is a PP-G-MAH layer.

6. The packaging film according to claim 1, characterized in that The thickness of the first adhesive layer is 250 μm to 350 μm; The thickness of the second adhesive layer is 350 μm to 450 μm; The thickness of the adhesive layer is 50 μm to 100 μm.

7. The packaging film according to claim 1, wherein: The first adhesive layer is an insulating adhesive layer; The first adhesive layer, the second adhesive layer and the bonding adhesive layer are all transparent film layers.

8. A thin film photovoltaic module, characterized in that: The encapsulating film according to any one of claims 1 to 7, further comprising: a thin-film solar cell chip, located on a surface of the first adhesive layer facing away from the bonding adhesive layer; The back panel glass is located on the surface of the second adhesive layer facing away from the bonding adhesive layer.

9. The thin-film photovoltaic module according to claim 8, characterized in that: The first adhesive layer is suitable for connecting the thin-film solar cell chip; The second adhesive layer is suitable for connecting to the back panel glass.

10. The thin-film photovoltaic module according to claim 8, characterized in that: The thin-film solar cell chip includes a transparent or semi-transparent substrate and a thin-film solar cell prepared on the substrate; The thin film solar cell includes a perovskite solar cell.

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